The present disclosure relates to a sintering apparatus that is preferred for preparing a target material and the like for the sputtering film formation, a method of manufacturing a sintered compact using such a sintering apparatus, and a target material.
In a thin-film formation process using a sputtering method, a composition and a density of a target material significantly determine the properties of such a process and the characteristics of a device to be manufactured by the film formation. Therefore, a target material having the high density and high compositional homogeneity has been desired.
At present, in the manufacturing of a target material for sputtering, the use of a vacuum hot pressing apparatus (for example, see Japanese Unexamined Patent Application Publication No. H6-297198 and No. H9-318273) has become mainstream. In the vacuum hot pressing apparatus, the controllability and uniformity of the density, crystallinity, composition, and the like are significantly improved by carrying out pressure sintering under vacuum or under controlled atmosphere.
On the other hand, in a case of this method, a heating and sintering section is configured of a robust housing capable of being immune to high vacuum, leading to a complicate and expensive apparatus configuration. Further, an increase in volume of a container and thermal capacity causes much time to be taken for vacuuming, atmosphere replacement, heating, and cooling, resulting in a longer takt time and degradation in productivity.
On the contrary, a hot pressing apparatus having no housing or only a simple enclosure that carries out sintering under an air atmosphere is not comparable to a vacuum hot pressing apparatus in terms of the atmosphere control, but is advantageous in a simplified structure and a decrease in overall thermal capacity. It is possible to remove a material to be sintered together with a mold (dice) from the hot pressing apparatus at the stage when sintering is completed, which ensures a reduced takt time and improved productivity.